Receiving system for wireless telegraphy and telephony



Aug. 18, 1925.

r H. J. ROUND RECEIVING SYSTEM FOR' WIRELESS TELEGRAPHY AND TELEPHONY Filed March 51, 1920 Patented Aug. 18', 19255. I

HENRY JOSEPH ROUND, 0]? MUSWELL HILL, LQ'NDON, ENGLAND, ASSIGNOR TO THE RADIO CORPORATION OF AMERICA, A QORPORATION OF DELAWARE.

RECEIVING SYSTEM FOR WIRELESS TELEGRAPHX AND TELEPHONY.

Application med march 31, 1920. Serial ml. 370,173.

T o allgwhom it may concern:

Be it known that I HENRY J QSEPH ROUND, a subject of the King of Great Britain, residin at 9 Woodberry Crescent, Muswell Hill, fondon, England, have invented 'new and useful Improvements in Receiving Systems for .Wireless Telegraphy and Telephony, of which the following is a be made to balance one another with the re-- specificatlon.

This invention relates to improved 'methods of receiving wireless signals by which incoming signals can be affected as desired and may when it is so required be rendered ineffective.

. It is well known that when two high frequency currents of different frequency are caused to act simultaneously in a circuit the result when rectified. and passed through a telephone produces a. beat tone. In certain A cases this beat tone is beyond the frequency for audibility and a further process is necessary in order to makeit audible.

It has now been discovered that the phase of the beat tone can be altered by altering the phase of either of the two original high frequency currents. Thus, if one of the high frequency currents has its phase shifted through at degrees, the phase of the other current remaining constant, the beat tone shifts through at degrees also.

According to this invention incoming signals are heterodyned so as to produce a beat current and on this beat current is superimposed another current of a frequency equal to that of the beat current, the phase of the heterodyne or of the signals'being adjusted so'as to renderv the phase of the beat current such that the beat cur-' rent can be added algebraically to the other current in an desired manner.

" Thus if it 1s desired to eliminate the effect of certain signals, these signals are heterodyned so that on each of two receiving aerials, which. are spaced a fraction of thewave length of the "signals apart, there may be the same phase difference between the signals and the heterodyne, and therefore the beat currents in the two aerials can sult'that the signals are ineffective.-

The invention "is illustrated by the accompanying drawing in which Figure 1 is a diagram offrequencies while Figure 2 is a diagram illustrating a receiving station.

' In Figure 1 the curves A, A, and B, B re resent two frequencies and the curve 6,8,

represents these two added. The envelope D, D, represents approximately the rectie fied beattone due to these two frequencies. The curve E, E, represents the same frequency as the curve B, B, but altered in phase through 180 and the envelope F, F, represents approximately the rectified beat tone due to A, A, and E, E, an d is similar to D, D, but 180 out of phase with it. In the same wa a reversal of phase of A, A, leaving B, unaltered, Wlll produce the same effect and any intermediate change of phase will be likewise reproduced in the envelope.

' Figure 2 shows how this invention may be applied to the elimination of signals. A, are two receiving aerials spaced-a frac tion of the wave length of the signals apart. They are coupled to rectifiers R R connected to low frequency transformers T T which are connected by lines L L to a balancing transformer T with a telephone X on a tertiary winding.

A is a transmitting aerial situated in the plane of A} and A and capable of supplying heterodyne current.

If signals arrive from a distant station in the plane of A A A then, since the difference in phase between the signals and the heterodyne from A is the same on aerial A as on aerial A except for a second order difference due to the slight difference of frequency between the signals and the heter- A odyne current the beat tones produced after rectification of the currents in aerials A v and A will balance in transformer T and thus the signals will not be efiective in the telephone, but if signals come from any direction other than that of the plane through A, A A the beat tones due to the currents in' aerials At and A will be different in phase: and will not balance except in particular instances where the currents produced in the aerials by the signals are or 180 apart.

As the lines L L only have to carry low frequency beat currents they maybe ora number of aerials such as those used in parabolic formations may be similarly connected to a distant detector.

What I claim is 1. A method of receiving Wireless signals which consists in combining a slightly different heterodyne frequency with the siging the beat current, superimposing on the beat current another current of the same frequency and controlling the phase of the heterodyne or of the signals to bring the phase of the beat current to a desired phase relative to the other current.

3.'A step in the method of, eliminating certain wireless signals which consists in receiving the signals on aerials spaced apart a fraction of the signal wave length heterodyning the signalsso that at any moment there may be. substantially the same phase difference between the heterodyne and the signals on each of said aerials.

4. A method of eliminating certain wireless signals whi'ch consists in receiving such signals on aerials s aced apart a fractlon of the signal wave 1 signals so that at any moment there may be substantially the same phase difference between the heterodyne and the signals .on each of said aerials and combining the beat currents in opposition.

5. A method of eliminating-wireless signals which consists in receiving such signals on aerials spaced apart a, fraction of the signal wave length heterodyning'the signals so that there may be substantially the same phase difference between the heterodyne and the signals on each of said aerials rectifying the beat currents thus produced and combining the rectified currents.

6. A method of eliminating wireless signals which consists in receiving the si als on aerials spaced apart a fraction 0 the wave length combining a slightly different heterodyne frequency with the signals so that there may be substantially the same phase difference between the heterodyne and the signals on each of said aerials, rectifymg the beat currents thus roduced and adding algebraically the rectified currents.

ength heterodyning the 7. A method of receiving wireless signals which consists in receiving the signals in a plurality of aerials, heterodyning all of the signal currents from the same source to produce a plurality of beat frequency currents of the same frequency, combining the beat frequency currents and adjustingsthe phase of the heterodyne or the signs. to cause said beat frequency currents to combine in a desired manner.

8. A wireless receiving system comprising a plurality of receiving aerials, means for generating a heterodyne frequency adapted to produce a beat with the received signals, means for supplying said heterodyne frequency to said receiving aerials in different phase relation to control the phase of the beat currents produced, and means for combining said beat currents.

9. A wireless receiving system comprising a plurality of receiving aerials, a heterodyne for producing a frequency adapted to beat with received signals, means for supplying said heterodyne frequency to said aeria s in different phase relation and means for combining the beat currents produced.

10. In radio signaling, the method of obtainingreception directionally selective in a horizontal plane'with a plurality of spaced aerials which comprises supplying .the same heterodyne frequency to said aerials, and

controlling the phase relationof such heterodyne frequencies with respect to each other to provide for zero indication of signals from a predetermined direction.

' 1-1. In radio signaling, the method of obtaining directional selectivity with a plurality of aerials which comprises supplying such aerials with the same heterodyne frequency and controlling the relative phase relation of said heterodyne frequency at each aerial to provide for zero response to signals from a predetermined direction.

12. In radio receiving the method of obtaining directional selectivity which comprises the step of supplying a plurality of receiving aerials with the same heterodyne frequency, and controlling the phase relations of said heterodyne requency at said aerials with respect to each other to obtain the desired directional selectivity.

13. The method of controlling the relative phase of a plurality of currents resulting from the interaction of com onent currents of different frequencies whic consists in controlling the phase relation of one of said component currents to produce the desired phase relation of said resultant currents.

IIENRY JOSEPH ROUND. 

